Room temperature-curable organopolysiloxane composition

Abstract

Provided is a room temperature-curable organopolysiloxane composition having excellent storage stability in a sealed packaging form and having less odor.　This room temperature-curable organopolysiloxane composition comprises the following (A) component, (B) component, (C) component, and (D) component. (A) is a diorganopolysiloxane having a viscosity of 20-1,000,000 mPa∙s at 25ºC. (B) is an alkoxy or enoxysilane compound in which a functional group bonded to a silicon atom is a hydrocarbon group that does not contain a heteroatom other than an oxygen atom, and / or a partially hydrolyzed condensate thereof. (C) is a curing catalyst. (D) is an organosilicon compound.

Description

Room temperature curable organopolysiloxane composition

[0001] The present invention relates to a room-temperature-curable organopolysiloxane composition that cures at room temperature to form a silicone rubber. Specifically, the present invention relates to a room-temperature-curable organopolysiloxane composition that, after curing, provides a silicone rubber that has excellent self-adhesion to glass, various metals, resins, etc., and that has excellent storage stability, particularly when packaged in a sealed container, and has a low odor.

[0002] Among conventional organopolysiloxane compositions that cure at room temperature to form rubber-like elastomers, so-called one-component (single-liquid) room-temperature-curable organopolysiloxane compositions undergo a curing reaction upon contact with moisture in the air. These room-temperature-curable organopolysiloxane compositions eliminate the need for complicated weighing and mixing of base polymers, crosslinking agents, catalysts, etc. immediately before use, eliminating the risk of formulation errors. Furthermore, they generally exhibit excellent adhesion to a wide range of substrates, even without the use of a primer. For this reason, these room-temperature-curable organopolysiloxane compositions are widely used as elastic adhesives and coating materials in the electrical and electronics industries, as well as in construction sealants.

[0003] Such one-component room-temperature-curable organopolysiloxane compositions are often classified by the compounds released from the composition upon contact with moisture in the air, and representative examples include deacetic acid-, deoxime-, deamidation-, dehydroxylamine-, acetone-, and dealcohol-type organopolysiloxane compositions. Among these, dealcohol-type organopolysiloxane compositions that cure by releasing alcohol are particularly preferred for their low odor, non-corrosion to metals such as copper and iron, excellent self-adhesion (adhesion to various substrates after curing when no primer is used), and excellent adhesion durability.

[0004] However, although one-component dealcohol-type organopolysiloxane compositions have the above-mentioned excellent properties for a short period after production, they have drawbacks in storage stability, such as the loss of the properties they had immediately after production over time during storage, depending on the formulation. Furthermore, storage in direct sunlight at the site of use or in a high-temperature environment exceeding 40°C, which is often the case when stored in a container during transport, can cause problems such as a loss of the original properties or poor curing, even for a relatively short period of time.

[0005] One-component, dealcohol-removing organopolysiloxane compositions have long been proposed, and Japanese Patent Publication No. 39-27643 (Patent Document 1) proposes a composition comprising a terminally hydroxyl-blocked organopolysiloxane, an alkoxysilane, and a titanium compound. Japanese Patent Laid-Open Publication No. 55-43119 (Patent Document 2) proposes a composition comprising an organopolysiloxane having alkoxysiloxy groups at its terminals, an alkoxysilane, and an alkoxytitanium. However, these compositions have problems, such as the inability to obtain storage stability when calcium carbonate is added to impart good physical properties to the sealant, resulting in the composition failing to obtain the desired properties when stored for a long period of time, or the composition failing to cure when stored in a high-temperature environment exceeding 50°C.

[0006] U.S. Patent No. 4,417,042 (Patent Document 3) proposes a composition that improves storage stability by using a scavenger with an organic silazane structure to capture alcohol compounds within the composition. This technology improved storage stability, particularly when hexamethyldisilazane was selected as the scavenger. However, because hexamethyldisilazane has a low boiling point, is highly volatile, and has a pungent odor, compositions containing it also produce a strong odor. Furthermore, the by-products of ammonia and trimethylmethoxysilane produced during alcohol capture further increase the odor over time, thereby undermining the low odor advantage of the dealcoholization type. Furthermore, the use of high-boiling silazanes, such as cyclic silazanes, does not solve the odor problem caused by the by-production of ammonia and low-boiling alkoxysilanes. Furthermore, the high cost of cyclic silazanes increases the cost of industrial use.

[0007] Japanese Patent Publication No. 7-39547 (Patent Document 4) proposes a composition that exhibits excellent storage stability in a sealed state. The composition proposed therein requires the use of a polymer in which an alkoxysilyl alkylene group is modified at the end of an organopolysiloxane, and the preparation of this polymer raises problems such as high industrial costs.

[0008] Furthermore, Japanese Patent Laid-Open No. 2-38309 (Patent Document 5) and Japanese Patent Laid-Open No. 2003-176411 (Patent Document 6) propose compositions using calcium carbonate treated with a fatty acid ester. These compositions have problems such as insufficient storage stability when stored at high temperatures exceeding 50°C, and because calcium carbonate treated with a fatty acid ester is used as a special filler, compositions containing a large amount of the filler are expensive.

[0009] Japanese Patent Publication No. 39-27643 Publication No. 55-43119 US Pat.

[0010] Accordingly, an object of the present invention is to provide a dealcohol-curable room-temperature organopolysiloxane composition that cures at room temperature in the presence of atmospheric moisture to give a cured silicone rubber product, and in particular to provide a room-temperature curable organopolysiloxane composition that has excellent storage stability when packaged in a sealed container and has little odor.

[0011]

[0006] As a result of extensive research to achieve the above object, the present inventors have discovered that an organopolysiloxane composition having a specific composition can solve the above problems, and have completed the present invention. Specifically, the present invention provides the following room-temperature-curable organopolysiloxane composition.

[0012] [1] A room-temperature-curable organopolysiloxane composition comprising the following components (A), (B), (C), and (D): (A) 100 parts by mass of a diorganopolysiloxane represented by the following general formula (1) having a viscosity at 25°C of 20 to 1,000,000 mPa·s: (In formula (1), R 1 are independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxyalkyl group having 2 to 10 carbon atoms, and R 2 are independently a group having 1 to 10 carbon atoms selected from monovalent hydrocarbon groups, halogenated monovalent hydrocarbon groups, and cyanoalkyl groups. 1 is a hydrogen atom, the value is 2, and R 1 is 0 or 1 when it is an alkyl group having 1 to 10 carbon atoms or an alkoxyalkyl group having 2 to 10 carbon atoms. Y is an oxygen atom, a divalent hydrocarbon group having 1 to 6 carbon atoms, or a group represented by the following general formula (2). n is a number that gives the diorganopolysiloxane a viscosity at 25°C of 20 to 1,000,000 mPa·s. (In formula (2), R 2are independently a group having 1 to 10 carbon atoms selected from a monovalent hydrocarbon group, a halogenated monovalent hydrocarbon group, and a cyanoalkyl group, and Z is a divalent hydrocarbon group having 1 to 6 carbon atoms.) (B) an alkoxy or enoxy silane compound and / or a partial hydrolysis condensate thereof, in which the functional group bonded to the silicon atom is a hydrocarbon group containing no heteroatoms other than oxygen atoms: 0.5 to 20 parts by mass; (C) a curing catalyst: 0.001 to 20 parts by mass; (D) an organosilicon compound represented by the following general formula (3): 0.1 to 5 parts by mass: (In formula (3), R 1 are independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxyalkyl group having 2 to 10 carbon atoms, and R 2 are independently a group having 1 to 10 carbon atoms selected from a monovalent hydrocarbon group, a halogenated monovalent hydrocarbon group, and a cyanoalkyl group; R 3 are independently an alkylene group having 1 to 10 carbon atoms, and m is a number from 1 to 3.) [2] The room-temperature-curable organopolysiloxane composition according to [1], wherein component (C) is a tin compound. [3] The room-temperature-curable organopolysiloxane composition according to [1] or [2], further comprising 1 to 300 parts by mass of (E) an inorganic filler per 100 parts by mass of component (A). [4] The room-temperature-curable organopolysiloxane composition according to any one of [1] to [3], further comprising 0.1 to 20 parts by mass of (F) a silane coupling agent per 100 parts by mass of component (A). [5] The room-temperature-curable organopolysiloxane composition according to any one of [1] to [4], which is filled in a cartridge made of polyethylene and / or polypropylene.

[0013] The room-temperature-curable organopolysiloxane composition of the present invention has excellent storage stability when packaged in a sealed container, has little odor, and after curing gives a cured product that has excellent adhesion to glass, painted aluminum, and the like, even without the use of a primer, making it useful as a coating material, sealant, and adhesive.

[0014] The room-temperature-curable organopolysiloxane composition of the present invention comprises the following components (A), (B), (C), and (D).

[0015] Component (A) The diorganopolysiloxane of component (A) is the main component of the composition. It is a diorganopolysiloxane represented by the following general formula (1) and having hydroxy, alkoxy, or alkoxyalkoxy groups at both ends of the molecular chain. Furthermore, if the viscosity is too low, the rubber elasticity after curing will be poor, while if it is too high, workability will be reduced. Therefore, the viscosity at 25°C must be within the range of 20 to 1,000,000 mPa·s, and preferably within the range of 100 to 100,000 mPa·s. This viscosity is measured using a rotational viscometer at 25°C. The molecular structure of this organopolysiloxane is substantially linear, i.e., the siloxane bond chain structure consisting of SiO is linear, but a portion of the molecular chain, such as the alkyl group side chain, may be branched. (In formula (1), R 1 are independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxyalkyl group having 2 to 10 carbon atoms, and R 2 are independently a group having 1 to 10 carbon atoms selected from monovalent hydrocarbon groups, halogenated monovalent hydrocarbon groups, and cyanoalkyl groups. 1 is a hydrogen atom, the value is 2, and R 1 is 0 or 1 when it is an alkyl group having 1 to 10 carbon atoms or an alkoxyalkyl group having 2 to 10 carbon atoms. Y is an oxygen atom, a divalent hydrocarbon group having 1 to 6 carbon atoms, or a group represented by the following general formula (2). n is a number that gives the diorganopolysiloxane a viscosity at 25°C of 20 to 1,000,000 mPa·s.

[0016] In formula (1), R 1 Examples of the alkyl group include a hydrogen atom, an alkyl group having 1 to 10 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, and an octyl group; and an alkoxyalkyl group having 2 to 10 carbon atoms such as a methoxymethyl group, a methoxyethyl group, and an ethoxymethyl group. Of these, a hydrogen atom, a methyl group, or an ethyl group is preferred.

[0017] In formula (1), R 2Examples of the alkyl group include groups having 1 to 10 carbon atoms selected from monovalent hydrocarbon groups, halogenated monovalent hydrocarbon groups, and cyanoalkyl groups. Examples of monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, butyl, and octyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; alkenyl groups such as vinyl and allyl; aryl groups such as phenyl, tolyl, and naphthyl; and aralkyl groups such as benzyl, phenylethyl, and phenylpropyl. Examples of halogenated monovalent hydrocarbon groups include trifluoropropyl and chloropropyl groups. Examples of cyanoalkyl groups include β-cyanoethyl and γ-cyanopropyl groups. Of these, a methyl group is preferred.

[0018] a is R 1 is a hydrogen atom, the value is 2, and R 1 is 0 or 1 when it is an alkyl group having 1 to 10 carbon atoms or an alkoxyalkyl group having 2 to 10 carbon atoms.

[0019] In formula (1), Y is an oxygen atom, a divalent hydrocarbon group having 1 to 6 carbon atoms, or a group represented by the following general formula (2). As the divalent hydrocarbon group having 1 to 6 carbon atoms, an alkylene group having 1 to 6 carbon atoms such as methylene, ethylene, propylene, trimethylene, butylene, tetramethylene, hexene, or hexamethylene is preferred, with an ethylene group being particularly preferred. The hydrogen atom of the alkylene group may be substituted with a monovalent hydrocarbon group such as a methyl group. (In formula (2), R 2 are independently a group having 1 to 10 carbon atoms selected from a monovalent hydrocarbon group, a halogenated monovalent hydrocarbon group, and a cyanoalkyl group, and Z is a divalent hydrocarbon group having 1 to 6 carbon atoms.

[0020] In formula (2), R 2 is R in formula (1) 2In formula (2), the divalent hydrocarbon group represented by Z is preferably an alkylene group having 1 to 6 carbon atoms, such as methylene, ethylene, propylene, trimethylene, butylene, tetramethylene, hexene, or hexamethylene, with ethylene being particularly preferred. The hydrogen atoms of the alkylene group may be substituted with monovalent hydrocarbon groups, such as methyl.

[0021] In formula (1), n ​​is a number that results in a viscosity of 20 to 1,000,000 mPa s at 25°C. Component (A) may be used alone or in combination of two or more types. Component (A) can be produced by a well-known method.

[0022] The content of component (A) in the entire composition of the present invention is preferably 20 to 95% by mass, and more preferably 30 to 90% by mass.

[0023] Component (B) is an alkoxy or enoxy silane compound and / or a partial hydrolysis condensate thereof, in which the functional group bonded to the silicon atom is a hydrocarbon group that does not contain heteroatoms such as nitrogen (N) or sulfur (S) other than oxygen (O), and serves to cure the room-temperature-curable organopolysiloxane composition of the present invention and to adjust the curing rate by adjusting the amount added. Furthermore, component (B) is preferably one in which the functional group bonded to the silicon atom, other than the alkoxy or enoxy group, does not contain heteroatoms such as oxygen (O), nitrogen (N), or sulfur (S).

[0024] Examples of the alkoxy or enoxy silane of component (B) include alkoxy group-containing compounds such as tetramethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, tetraethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, isobutyltrimethoxysilane, normal butyltrimethoxysilane, normal hexyltrimethoxysilane, decyltrimethoxysilane, and partial hydrolysis condensates thereof; substituted alkoxy group-containing compounds such as tetrakis(2-ethoxyethoxy)silane, methyltris(2-methoxyethoxy)silane, vinyl(2-ethoxyethoxy)silane, phenyltris(2-methoxyethoxy)silane, and partial hydrolysis condensates thereof; methyltriisopropenoxysilane, vinyltriisopropenoxysilane, phenyltris(2-methoxyethoxy)silane, and partial hydrolysis condensates thereof; enoxy group-containing compounds such as phenyltriisopropenoxysilane, dimethyldiisopropenoxysilane, methylvinyldiisopropenoxysilane, and partial hydrolysis condensates thereof; 1,3-bis[(trimethoxysilyl)ethyl]-1,1,3,3-tetramethyldisiloxane, 1,3-bis[(triethoxysilyl)ethyl]-1,1,3,3-tetramethyldisiloxane, 1,3-bis[(methyldimethoxysilyl)ethyl]-1,1,3,3-tetramethyldisiloxane; Examples of the alkoxysilylsiloxane include bisalkoxysilyldisiloxane compounds such as 1-[(trimethoxysilyl)ethyl]-3-[(triethoxysilyl)ethyl]-1,1,3,3-tetramethyldisiloxane, 1-[(methyldimethoxysilyl)ethyl]-3-[(trimethoxysilyl)ethyl]-1,1,3,3-tetramethyldisiloxane, and bisalkoxysilylalkane compounds such as 1,2-bis(trimethoxysilyl)ethane and 1,6-bis(trimethoxysilyl)hexane.

[0025] In the present invention, the alkoxy or enoxy silane may be used alone or in combination of two or more. Among them, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, decyltrimethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane, which can be obtained industrially at relatively low cost, are preferred, and methyltrimethoxysilane is particularly preferred.

[0026] The amount of component (B) blended is 0.5 to 20 parts by mass, and preferably 0.5 to 15 parts by mass, per 100 parts by mass of component (A). 1 When is a hydrogen atom, in order to obtain good curability and storage stability, the number of moles of alkoxy groups in component (B) per mole of hydroxyl groups in component (A) is preferably greater than 1 mol, and more preferably 2 to 30 mol.

[0027] Component (C) Component (C) is a curing catalyst, and examples of the curing catalyst include organic carboxylates, alkoxides, and chelate compounds of metals such as tin, aluminum, zirconium, titanium, iron, antimony, bismuth, and manganese. More specifically, these include tin compounds such as dibutyltin dilaurate, dibutyltin dioctoate, dioctyltin dilaurate, dibutyltin maleate ester, dimethyltin dineodecanoate, dibutyltin dimethoxide, dioctyltin dineodecanoate, and stannous octoate; organic aluminum compounds such as aluminum tris(acetylacetonate), aluminum tris(ethylacetoacetate)diisopropoxyaluminum ethylacetoacetate, and triethoxyaluminum; zirconium tetrakis(acetylacetonate), tetraisopropoxyzirconium, tetrabutoxyzirconium, and tributoxyzirconium acetone. Examples of suitable compounds include organic zirconium compounds such as tetra-normal-butoxytitanium, tetrakis(2-ethylhexoxy)titanium, tetraisopropoxytitanium, and tetratertiary-butoxytitanium; titanium chelate compounds such as diisopropoxybis(acetylacetonato)titanium, diisopropoxybis(ethylacetoacetate)titanium, and dibutoxybis(methylacetoacetate)titanium; and amine compounds and salts thereof such as dibutylamine, laurylamine, tetramethylguanidine, and tetramethylguanidylpropyltrimethoxysilane. These compounds can be used alone or in combination of two or more. Adding a tin compound or a titanium compound is preferred because it provides excellent properties such as the appearance and storage stability of the composition of the present invention, with tin compounds being particularly preferred. The amount of component (C) added is 0.001 to 20 parts by mass, preferably 0.01 to 10 parts by mass, per 100 parts by mass of component (A).

[0028] Component (D) Component (D) is an organosilicon compound represented by the following formula (3). (In formula (3), R 1are independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxyalkyl group having 2 to 10 carbon atoms, and R 2 are independently a group having 1 to 10 carbon atoms selected from a monovalent hydrocarbon group, a halogenated monovalent hydrocarbon group, and a cyanoalkyl group; R 3 are independently an alkylene group having 1 to 10 carbon atoms, and m is a number from 1 to 3.

[0029] In formula (3), R 1 and R 2 are R in formula (1), respectively. 1 and R 2 In formula (3), R 3 are independently an alkylene group having 1 to 10 carbon atoms such as a methylene group, a dimethylene group, a trimethylene group, or a butylene group, and among these, a methylene group, a dimethylene group, or a trimethylene group is preferred.

[0030] Specific examples of the component (D) include the following:

[0031] The amount of component (D) added is 0.1 to 5 parts by mass, and preferably 0.2 to 3 parts by mass, per 100 parts by mass of component (A). If the amount is less than 0.1 part by mass, the effect of imparting sufficient storage stability to the composition will not be obtained, while if it exceeds 5 parts by mass, the self-adhesive properties of the composition may decrease.

[0032] In addition to the above-described components (A) to (D), the composition of the present invention may also contain an inorganic filler (E). Component (E) functions to impart good mechanical properties to the cured product of the composition of the present invention.

[0033] Examples of component (E) include wet silica, dry-process fumed silica, silicas whose surfaces have been treated with chlorosilanes such as dichlorodimethylsilane or trichloromethylsilane, silazanes such as hexamethyldisilazane, or siloxanes such as octamethyltetrasiloxane, heavy (or ground) calcium carbonate, precipitated calcium carbonate, and powders of these calcium carbonates surface-treated with organic acids such as fatty acids or resin acids, alkali metal salts of organic acids, or organic acid esters. In the present invention, the presence or absence of surface treatment and the type of treatment agent are not limited. Fumed silica, precipitated calcium carbonate, heavy calcium carbonate, alumina, aluminum hydroxide, and other inorganic fillers can be used alone or in combination of two or more, depending on the desired properties of the composition. The BET specific surface area of ​​component (E) is not particularly limited, but for fumed silica, it can be 30 to 400 m. 2 / g, and in the case of calcium carbonate obtained by treating the surface of precipitated calcium carbonate with various organic substances, it is preferably 5 to 50 m 2 / g, and particularly preferably 10 to 40m 2 The calcium carbonate produced by the precipitation method, whose surface is not treated, has agglomerated particles during production and has a spindle-shaped primary particle size of preferably 1 to 20 m. 2 / g, particularly preferably 3 to 10 m 2 The heavy calcium carbonate, whether surface-untreated or surface-treated with an organic substance, preferably has a surface roughness of 1 to 15 m / g. 2 / g.

[0034] When component (E) is added, the blending amount is preferably in the range of 1 to 300 parts by mass, and more preferably in the range of 5 to 200 parts by mass, per 100 parts by mass of component (A). If the blending amount of component (E) is less than the lower limit of the above range, the properties of component (E) may not be obtained, whereas if the blending amount exceeds the upper limit of the above range, the handling and workability of the composition of the present invention may be impaired.

[0035] Component (F) In addition to the above-described components (A) to (E), the composition of the present invention may contain a silane coupling agent (F). Component (F) further improves the adhesion of the composition of the present invention to various substrates.

[0036] Component (F) is a compound other than components (B) and (D), and is preferably a compound known in the art. In particular, compounds having an alkoxysilyl group or an alkenoxysilyl group as a hydrolyzable group are preferred, such as γ-methacryloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, 3-(N-aminomethylbenzylamino)propyltrimethoxysilane, 3-(N-aminomethylbenzylamino)propyltriethoxy ... Examples include methoxysilane, N,N'-bis[3-(trimethoxysilyl)propyl]ethylenediamine, N,N-bis[3-(trimethoxysilyl)propyl]amine, γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltriisopropenoxysilane, γ-glycidoxypropylmethyldiisopropenoxysilane, a reaction product of a (meth)acrylic silane and an aminosilane, a reaction product of an epoxy silane and an aminosilane, a reaction product of an aminosilane and a silane containing a halogenated alkyl group, etc. In particular, it is preferable to use a silane coupling agent containing at least one amino group in the molecule.

[0037] When this silane coupling agent is added, the blending amount is preferably 0.1 to 20 parts by mass, and particularly preferably 0.5 to 10 parts by mass, per 100 parts by mass of component (A). Less than 0.1 part by mass does not provide the improvement in adhesion achieved by adding component (F), while more than 20 parts by mass is not only uneconomical but may also result in a decrease in hot water resistance.

[0038] [Other Components] In addition to the components described above, commonly known additives may also be used, provided they do not impair the effects of the present invention. Examples of additives include, in addition to component (E), fine quartz powder, titanium dioxide powder, diatomaceous earth powder, aluminum hydroxide powder, fine alumina powder, magnesia powder, zinc oxide powder, and fine powder inorganic fillers obtained by surface-treating these with silanes, silazanes, low-polymerization polysiloxanes, or the like. The amount of such inorganic fillers added is 10 to 200 parts by mass, preferably 30 to 150 parts by mass, per 100 parts by mass of component (A). Other additives are components that impart a low modulus to the silicone rubber after curing. Examples of suitable additives include dialkoxysilanes such as diphenyldimethoxysilane and dimethyldimethoxysilane, dimethylpolysiloxanes end-blocked with trimethylsiloxy groups, isoparaffin, platinum compounds as flame retardants, zinc carbonate powder, polyethers as thixotropy improvers as needed, colorants such as pigments, dyes and fluorescent brighteners, heat resistance improvers such as red iron oxide and cerium oxide, cold resistance improvers, rust inhibitors, mildew inhibitors, antibacterial agents, etc. Solvents such as toluene, xylene, solvent volatile oils, cyclohexane, methylcyclohexane, and low-boiling point isoparaffins may also be added.

[0039] Production Method The composition of the present invention can be produced as a so-called one-component, dealcohol-removing organopolysiloxane composition by blending the above-described components (A) to (D) and, if necessary, components (E) and (F), and other components, in a dry atmosphere according to a conventional method. The composition is then preferably sealed and packaged for storage. Cylindrical cartridges made of polyethylene or polypropylene are the most preferred sealed packaging containers for maximizing the effects of the composition of the present invention. The composition of the present invention typically cures in the presence of atmospheric moisture when left in an ambient atmosphere. The composition of the present invention can be used for a variety of applications, but is particularly useful as a coating material, sealant, or adhesive.

[0040] Examples, comparative examples, and synthesis examples of the present invention will be described below, but the present invention is not limited to these examples. The viscosity values ​​in the examples are measured at 25°C using a rotational viscometer (TVB-10M manufactured by Toki Sangyo Co., Ltd.), and all parts mean parts by mass. All compositions of the present invention were prepared using a "mixing stirrer (model: 5DMV-01-r)" manufactured by Dalton Co., Ltd.

[0041] Synthesis Example 1 Into a 1 L separable flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer, 92.5 g (0.50 mol) of an organosilicon compound represented by the following formula (5), a toluene solution of platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (0.5 × 10 as platinum atoms), -5 122 g (1.00 mol) of trimethoxysilane was added dropwise over 1 hour at an internal temperature of 75 to 85°C. The mixture was then aged for 3 hours at 80°C. After aging was complete, distillation was carried out under reduced pressure to obtain 193 g of an organosilicon compound represented by the following formula (6):

[0042] Synthesis Example 2 A 1-L separable flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer was charged with 106 g (0.50 mol) of an organosilicon compound represented by the following formula (7) and a toluene solution of platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (0.5 × 10 mol as platinum atoms), and 122 g (1.00 mol) of trimethoxysilane was added dropwise over 1 hour at an internal temperature of 75 to 85°C. This was followed by aging for 3 hours at 80°C. After aging was complete, vacuum distillation was carried out to obtain 205 g of an organosilicon compound represented by the following formula (8).

[0043] Example 1 500 g (100 parts by mass) of dimethylpolysiloxane (viscosity 50,000 mPa·s) in which both molecular chain terminals were blocked with dimethoxymethylsiloxy groups, 25 g (5 parts by mass) of methyltrimethoxysilane, 10 g (2 parts by mass) of vinyltrimethoxysilane, and 2.5 g (0.5 parts by mass) of 3-(2-aminoethylamino)propyltrimethoxysilane were mixed uniformly at room temperature of 23° C. and atmospheric pressure for 10 minutes. After stopping the mixing, the mixture was allowed to stand for 18 hours in a sealed container at 23° C., and a BET specific surface area of ​​105 m was obtained. 2 To this was added 70 g (14 parts by mass) of fumed silica (MU-215, manufactured by Shin-Etsu Chemical Co., Ltd.) having a surface treated with dimethyldichlorosilane (1 / g), and mixed uniformly. Then, 200 g (40 parts by mass) of dimethylpolysiloxane (viscosity 100 mPa s) in which both molecular chain terminals were blocked with trimethylsiloxy groups, 8.5 g (1.7 parts by mass) of organosilicon compound 1 synthesized in Synthesis Example 1, and 1.5 g (0.3 parts by mass) of dioctyltin dineodecanoate were added, and the mixture was mixed under reduced pressure for 10 minutes while removing air bubbles until uniform, yielding organopolysiloxane composition 1.

[0044] [Example 2] Organopolysiloxane composition 2 was obtained in the same manner as in Example 1, except that the amount of organosilicon compound 1 synthesized in Synthesis Example 1 added was changed from 8.5 g (1.7 parts by mass) to 4.0 g (0.8 parts by mass).

[0045] Example 3 Organopolysiloxane composition 3 was prepared in the same manner as in Example 1, except that organosilicon compound 1 synthesized in Synthesis Example 1 was replaced with the same amount of organosilicon compound 2 synthesized in Synthesis Example 2.

[0046] Example 4 500 g (100 parts by mass) of dimethylpolysiloxane (viscosity 50,000 mPa·s) having one hydroxyl group (silanol group) bonded to a silicon atom at each end of the molecular chain, 25 g (5 parts by mass) of methyltrimethoxysilane, and 8.5 g (1.7 parts by mass) of 3-(2-aminoethylamino)propyltrimethoxysilane were uniformly mixed at room temperature of 23°C and atmospheric pressure for 10 minutes to prepare a mixture. After stopping the mixing, the mixture was allowed to stand for 18 hours in a sealed container at 23°C, and then a polymer having a BET specific surface area of ​​150 m was obtained. 270 g (14 parts by mass) of surface-untreated fumed silica (Konasil-150, manufactured by OCI Corporation) having a viscosity of 100 mPa s was added and mixed uniformly. Then, 200 g (40 parts by mass) of dimethylpolysiloxane (viscosity 100 mPa s) in which both molecular chain terminals were blocked with trimethylsiloxy groups, 8.5 g (1.7 parts by mass) of organosilicon compound 1 synthesized in Synthesis Example 1, 15 g (3 parts by mass) of a partial hydrolysis condensate of methyltrimethoxysilane, and 1.5 g (0.3 parts by mass) of dioctyltin dineodecanoate were added, and the mixture was mixed under reduced pressure for 10 minutes while removing air bubbles until uniform, yielding organopolysiloxane composition 4.

[0047] Comparative Example 1 500 g (100 parts by mass) of dimethylpolysiloxane (viscosity 50,000 mPa·s) having one hydroxyl group (silanol group) bonded to a silicon atom at each end of the molecular chain, 25 g (5 parts by mass) of methyltri(methylethylketoxime)silane, and 10 g (2 parts by mass) of vinyltri(methylethylketoxime)silane were mixed uniformly at room temperature of 23° C. and atmospheric pressure for 10 minutes to prepare a mixture. After stopping the mixing, the mixture was allowed to stand for 18 hours in a sealed container at 23° C., and then a polymer having a BET specific surface area of ​​105 m was obtained. 2 70 g (14 parts by mass) of fumed silica ("MU-215" manufactured by Shin-Etsu Chemical Co., Ltd.) surface-treated with 1 / g of dimethyldichlorosilane was added and mixed uniformly, followed by adding 200 g (40 parts by mass) of dimethylpolysiloxane (viscosity 100 mPa s) capped at both molecular chain ends with trimethylsiloxy groups, 4.0 g (0.8 parts by mass) of 3-(2-aminoethylamino)propyltrimethoxysilane, and 0.5 g (0.1 parts by mass) of dioctyltin dilaurate, and mixing was continued under reduced pressure for 10 minutes while removing air bubbles until uniform, yielding organopolysiloxane composition 5.

[0048] Comparative Example 2 Organopolysiloxane Composition 6 was obtained in the same manner as in Example 1, except that the organosilicon compound 1 prepared in Synthesis Example 1 was not added.

[0049] Comparative Example 3 Organopolysiloxane Composition 7 was obtained in the same manner as in Example 1, except that in Example 4, the organosilicon compound 1 prepared in Synthesis Example 1 was replaced with the same amount of N,N-bis(trimethylsilyl)-3-aminopropyltrimethoxysilane.

[0050] Comparative Example 4 Organopolysiloxane composition 8 was obtained in the same manner as in Example 1, except that the organosilicon compound 1 prepared in Synthesis Example 1 was replaced with the same amount of hexamethyldisilazane.

[0051] Comparative Example 5 Organopolysiloxane Composition 9 was obtained in the same manner as in Comparative Example 4, except that the amount of hexamethyldisilazane added was changed to 0.2 parts by mass.

[0052] Comparative Example 6 Organopolysiloxane composition 10 was obtained in the same manner as in Example 4, except that the organosilicon compound 1 prepared in Synthesis Example 1 was replaced with the same amount of hexamethyldisilazane.

[0053] The organopolysiloxane compositions prepared in the Examples and Comparative Examples were evaluated for physical properties, adhesion, and storage stability. Each evaluation was carried out according to the methods described below, and the results for the compositions obtained in the Examples and Comparative Examples are shown in Tables 1 and 2.

[0054] [Physical Properties] The prepared composition was extruded into a polyethylene frame and left to cure for 7 days under conditions of a temperature of 23°C and a relative humidity of 50%, to prepare a sheet having a thickness of 2 mm. The physical properties of this sheet were measured in accordance with JIS K 6249.

[0055] [Odor] When extruding the product into a polyethylene frame in the evaluation of the "physical properties," the evaluator checked the odor for 20 seconds by approaching the product with his / her nose up to 10 cm away under conditions of a temperature of 23°C and a relative humidity of 50%. The level of odor was evaluated on a six-point scale of "0" (odorless), "1" (barely detectable odor), "2" (weak odor that is recognizable), "3" (easily detectable odor), "4" (strong odor), and "5" (overpowering odor), with 0 to 2 being "low odor" and 3 to 5 being "unacceptable."

[0056] [Storage stability] The composition was placed in a cylindrical polyethylene sealant cartridge (volume 330 ml) and sealed with an inner stopper. This cartridge was stored for 28 days in a thermo-hygrostat controlled at a temperature of 70°C and a relative humidity of 20%, and then removed and left at a temperature of 23°C and a relative humidity of 50% for 1 day. The stored composition was then evaluated for physical properties and odor. Regarding storage stability of physical properties, a hardness that was less than ±5 points higher than the hardness before storage (immediately after preparation) was considered acceptable, and a hardness that was more than ±5 points higher than the hardness before storage (immediately after preparation) was considered unacceptable.

[0057]

[0058]

[0059] As can be seen from Tables 1 and 2, the organopolysiloxane compositions obtained in Examples 1 to 4 have low odor and exhibit excellent storage stability even when left under heated and humid conditions. Therefore, they are useful as waterproof sealants in construction and civil engineering applications, elastic adhesives and coating materials in the electrical and electronic industries, and the like.

Claims

1. A room-temperature-curable organopolysiloxane composition comprising the following components (A), (B), (C), and (D): (A) 100 parts by mass of a diorganopolysiloxane represented by the following general formula (1) having a viscosity at 25°C of 20 to 1,000,000 mPa·s: (In formula (1), R 1 are independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxyalkyl group having 2 to 10 carbon atoms, and R 2 are independently a group having 1 to 10 carbon atoms selected from monovalent hydrocarbon groups, halogenated monovalent hydrocarbon groups, and cyanoalkyl groups. 1 is a hydrogen atom, the value is 2, and R 1 is 0 or 1 when it is an alkyl group having 1 to 10 carbon atoms or an alkoxyalkyl group having 2 to 10 carbon atoms. Y is an oxygen atom, a divalent hydrocarbon group having 1 to 6 carbon atoms, or a group represented by the following general formula (2). n is a number that gives the diorganopolysiloxane a viscosity at 25°C of 20 to 1,000,000 mPa·s. (In formula (2), R 2 are independently a group having 1 to 10 carbon atoms selected from a monovalent hydrocarbon group, a halogenated monovalent hydrocarbon group, and a cyanoalkyl group, and Z is a divalent hydrocarbon group having 1 to 6 carbon atoms.) (B) an alkoxy or enoxy silane compound and / or a partial hydrolysis condensate thereof, in which the functional group bonded to the silicon atom is a hydrocarbon group containing no heteroatoms other than oxygen atoms: 0.5 to 20 parts by mass; (C) a curing catalyst: 0.001 to 20 parts by mass; (D) an organosilicon compound represented by the following general formula (3): 0.1 to 5 parts by mass: (In formula (3), R 1 are independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxyalkyl group having 2 to 10 carbon atoms, and R 2 are independently a group having 1 to 10 carbon atoms selected from a monovalent hydrocarbon group, a halogenated monovalent hydrocarbon group, and a cyanoalkyl group; R 3 are independently an alkylene group having 1 to 10 carbon atoms, and m is a number from 1 to 3.

2. The room-temperature-curable organopolysiloxane composition according to claim 1, wherein component (C) is a tin compound.

3. The room-temperature-curable organopolysiloxane composition according to claim 1, further comprising (E) an inorganic filler in an amount of 1 to 300 parts by weight per 100 parts by weight of component (A).

4. The room-temperature-curable organopolysiloxane composition according to claim 1, further comprising 0.1 to 20 parts by weight of a silane coupling agent (F) per 100 parts by weight of component (A).

5. The room-temperature-curable organopolysiloxane composition according to claim 1, which is filled in a cartridge made of polyethylene and / or polypropylene.

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